1. Field
The present invention relates to data communication, and more particularly to techniques for testing different types of channels in a wireless (e.g., cdma2000) data communication system.
2. Background
Wireless data communication systems such as code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and others are widely used to provide various types of communication such as voice, data, and so on. For these systems, it is highly desirable to utilize the available resources (i.e., the available bandwidth and transmit power) as efficiently as possible. This typically entails transmitting as much data to as many users within as short a time period as supported by the conditions of the communication link.
To achieve the above goal, the performance of terminals may need to be evaluated in the factory and/or in the field. As part of a manufacturing process, the terminals may be tested to ensure that they comply with specified minimum performance criteria. And in the field, the performance of the terminals may be characterized and used to diagnose RF coverage and performance problems in the wireless data communication system.
In one conventional technique for characterizing the performance of a terminal, a known data pattern (e.g., generated by a pseudo-random number (PN) generator) is transmitted by an access point (or base station), received by the terminal, and sent back to the access point. This “loop-back” testing technique may be simple to implement but provides limited testing capabilities.
Many newer generation CDMA communication systems are capable of flexible operation. For example, data may be transmitted in bursts to the terminals, different types of data may be transmitted over different types of channels, the data rate may be allowed to vary from frame to frame on a particular channel, the processing of the data may also vary (e.g., from frame to frame and/or from channel to channel), and so on. The conventional loop-back testing technique is typically used to test a single traffic channel based on a defined set of test parameters, and may not be able to test various aspects of a newer generation CDMA system.
Moreover, different equipment vendors may support and/or implement different interfaces for testing the terminals. As a result, it is conceivable that equipment from one vendor may not be properly tested against, or in combination with, equipment from another vendor because of incompatible interfaces.
There is therefore a need in the art for techniques to test the performance of terminals and access points in CDMA systems.